Rotary duplicator



Nov. 5, 1940. w. R!TZERFELD ROTARY DUPLICATOR Filed Oct. .14, 1938 2 Sheets-Sheet 1 In venfor:

Aziorne y Nov. 5, 1940. w. RITZERFELD 2,

I ROTARY DUPLICATOR Filed Oct.-l4, 193s- 2 Sheets-Sheet 2 Preteen 5, 1940 l UNITED STATES PATENT OFFICE Application October 14, 1938, sem No. z34,sss

In Germany October 19, 1937 9 Claims. (Cl. 101-132) This invention relates to rotary duplicators with a device for bringing back the printed sheets towards the feeding side, i. e. towards that side on which the person operating the duplicator is to be found and has for its object to provide improvements therein. 'I'hese. known rotary duplicators consist in a printing drum with means for holding the original, a counter-pressure roller, a molstener in case of a mirror script original, if wanted supply means for the sheets to be printed upon and-also if wanted-means to take up the sheets printed upon.

The invention consists in a process of bringing back the discharged sheets, after passing the printing drum in a direction opposite to the feed direction at a speed which ls'preferably faster than the speed of rotation of the drum, towards the feeding side and therewith into the range of vision of the person operating the machine.

As means for carrying out this process according to the invention rolls or rollers are particularly suitable which can be moved by a printing drum periodically against a guiding roller for the printed sheets. The direction of rotation of these rolls or rollers depends on whether "the feeding of the sheets to be printed takes place below or above the drum. It is however important for a good working that these rolls or rollers have a greater speed of rotation than the printing drum itself.

Further details of the invention are given below by way of example and also illustrated by way of example in the attached drawings wherein: v

Fig. 1 is a side elevation of one form of device made in accordance with'the invention,

Fig. 2.is a partial plan,

Fig. 3 is a front view of the driving mecha- The sheet I, which is to be printed is pushed up with its front edge against the meeting line of the transporting rollers 2 and 3, which guide the sheet to the printing roller 4 or the pressure roller 5. After printing 'has taken place the printed sheet I below the guiding plate 6 arrives on the back receiving plate I, but only so far that the hinder end can still be gripped by.

rolls or a roller 8 and the rolls or roller 9 which can cooperate with it. The rollers 9 ,fiare disposed on an axle III which is borne in arms I l pivotally fastened at H. The arms H are tinder the influence of one or more springs l3. In consequence of this mounting the rollers 9 are in constant rapid revolution in the direction of the arrow, n-om'the'drive of the machine, can be those skilled in the art.

pressed against the rollers 9. For this purpose slots 14 (Fig. 2) are provided in the back receiving'plate 1, through which the rollers 9 can peneitr'ate. Known means, for example gear wheels, belts, chains or the like can be used for driving 5 the rolls or rollers 9 from the axle l5 of the motor It. In the form of construction illustrated a pulley I1 i provided on the motor axle l5 from which a belt I8 leads to a main pulley 20 rotatable round the shaft l9. On the shaft 10 I9 is secured a second pulley 2| from which a belt 22 drives the pulley.23 seated'on the axle l9 and therewith the axle I9 and the rollers 9. On the axle l9 of the main pulley 29 is further secured a pulley 24 which,- through the belt 25, drives a pulley 26 on the axle 21 of which a gear wheel 28 is secured; Through the gear wheel 29 the gear wheel 28 drives the gear wheel 38 which is secured on the axle 3| of the drum 4. The gear wheel 38 engages a gear wheel 32 which is provided on the axle 33 of the transporting roller 3 and gives the latter a rotary movement in'the direction of the arrow.

On the .front face of the drum 4 is fastened a curved member 34 which acts on the roller 35 of u the arm 36 secured on the axle 12. With the help -of this device the rollers 9 are pressed against the rollers 8 at the moment in which the hinder end of the printed-sheet lies between the rollers a and 9. By this means the sheet is conveyed back and on to the receiving table 31. An adjusting screw 38 serves for the regulation of the pressure stroke of the roller 9, whilst the spring l3 serves to regulate .the pressure.

From the following description, the operation 35 of the apparatus will be readily understood by Sheet l to be printed onto is placed on feed table 39 and is introduced into the bight of feed or transporting rollers '2 and 3 which convey the sheet to the printing drum 4 and the pressure roller 5. After the impression has been made by means of the printing drum and the pressure roller, guided by the lower surface of plate 6, the sheet is deposited on receiving plate 1 in -such a position that its 45 rear portion covers slots l4 provided in the receiving plate and is resting between rollers 8 and 9. During further rotation of printing drum 4, cam 34 will engage roller 35 on the end of arm 36' and will cause rotational displacerzent 50 of arm 36 and of arms ll mounted on a common shaft I2. This displacement causes rollers 9 rotated by belt 22 to extend through slots l4 and to be pressed against roller 8 whereby the printed sheet between rollers 8 and 9 will be engaged drum, a motor to rotate said drum, means to transfer the rotary movementof said motor'to and due to the direction of rotation of the circumferential surface of rollers 9- will be displaced in a direction opposite to that during the printing operation and will'be' deposited on collecting table 31. Due to the fact that .the circumferential speed of rollers 9 is higher than that of printing drum I, this returning displacement has a considerably higher speed than that of the printing displacement.

In theform of construction illustrated an observation opening, -i. e. a transparent disc. preferably a glass or Celluloid disc All isdisposed in the table 39 so that the person operating the machine can examine the sheet I which falls on the collecting table 31 before laying a new sheet on the feed table 39.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is: v

1. A rotary duplicator comprising a printing said printing drum, means to feed the blank sheets to said printing drum, means to press these blank sheets to the drum, means for taking up the sheets printed upon, rotary means for means being mounted on an axle, this axle being mounted in pivotally arranged arms, means .to-

rotate said rotary means and means to move said.

rotary means and said means for bringing back the printed sheets relatively to each other.

2. A rotary duplicator comprising a printing drum, means to rotate said drum, 9. table adapted to feed the blank sheets to said drum, a roller adapted to press said sheets against said drum, a table adapted to take up said sheets now printed, rotary elements adapted to bring back the printed sheets in a direction opposite to the feeding direction to the feeding side, said table for taking up the sheets being provided with slots allowing the rotar elements to penetrate, these elements being mounted on an axle, this axle being mounted in pivotally arranged arms. means for rotary driving said elements and means to move said elements periodically from.

the printing drum towards the table for taking up the sheets.

3. A rotary duplicator comprising a printing drum, means to rotate said drum, a table adapted to feed the blank sheets to said drum, a roller adapted to press said sheets againstsaid drum, an observation opening arranged in said feeding table, a table adapted to take up the printed sheets. means to bring the printed sheets to said table, said means consisting of rotary elements being rigidly mounted, rolls adapted to; bring back the printed sheets in a direction Opposite to the feeding direction at a speed faster than that of the printing. drum, said rollsmounted on an axle which is mounted in pivotally arranged arms, means to drive said rolls and means to move them'from the printing drum periodically to said rigidly mounted rotary elements.

4. A rotary duplicator comprising a printing drum, means to rotate said drum, a table adapt ed to feed the blank sheets to said drumjdroller adapted to press said sheets against said drum, an observation opening arranged in said feeding table, a table adapted to take up the printed sheets, means to bring the printed sheets to said table, said means consisting of rotary elements finally a table for taking up the printed sheets arrangedbelow an observation opening of said feeding table and. beneath the said table for taking up thesheets. I

5. A rotary duplicator comprising in combination a printing drum, means for rotating said drum, means for feeding clear sheets to be printed onto to said drum in a tangential direction, means for pressing said sheets against said drum, means. for receiving the printed sheets, means for returning said printed sheets to the feeding side of said duplicator in a direction opposite to the feeding direction'at a speed higher than the feeding speed, and means for driving said sheetreturning means.

6. A rotary duplicator comprising'in combination a printing drum, a pressure roller for pressing clear sheets to be printed onto against said drum, a pair of feed rollers for feeding said sheets to the bight of said printing drum and said pressure roller, a table for receiving the printed sheets and havingslots provided therein and said feed and sheet-returning rollers at predetermined relative velocities, a roller adapted to cooperate with said sheet-returning rollers rotatably mounted in a stationary position opposite to said rollers. pivotally mounted arms for supporting said sheet-returningrollers, a control arm for displacing said pivotally mounted arms from an inoperative into an operative position to have said sheet-returning rollers protrude through said slots and to press said printed sheets against said stationary roller and to return said sheet to the feeding side of said duplicator, and means for adjusting the pressure of said sheet-returning rollers.

'7. A rotary duplicator comprising in combination a printing drum, means for rotating said drum, means for feeding clear sheets to be printed onto said drum in a tangential direction, means for pressing said sheets to the drum, means'for receiving the printed sheets, means for returning said printed sheets to the feeding side of said duplicator in a direction opposite to the feeding direction at a speed higher than the feeding speed, means for continuously driving' said sheet-returning means, and means actuable by. said printing drum in a predetermined position thereof to displace said sheetreturning roller for each 01' said slots adapted to be displaced from an inoperative position into an operative position to protrude through said slots operating position with said sheet-returning rollers, means for driving said druni and said sheet-returnins rollers at predetermined relative velocities, and means operable by .said printing drum in a predetermined position thereof to periodically displace said sheet-returning rollers into their operative position and to return said printed sheet to theteeding side of said duplicator. V

9. The method .of duplicating copyableorizinsls onto clear sheets which comprises simultaneously by a pair of rotary cylindricai'suriaces to dilplace said sheet into the bight of sprinting. and counter pressure roller, passing. said sheet through the blght of said rollers to print; a. copy of said original onto the same, and subsequently engaging both sides or said printed copy sheetby another pair of rotary cylindrical, surfaces to displace'said sheet at a higher speed in the opposite direction and thereby to return the same 10 to the feed side.

ensasing both sides or a copy sheet" 

